§ 35.05 Justification; generally.

Unless otherwise limited by the ensuing provisions of this article
defining justifiable use of physical force, conduct which would
otherwise constitute an offense is justifiable and not criminal when:

1. Such conduct is required or authorized by law or by a judicial
decree, or is performed by a public servant in the reasonable exercise
of his official powers, duties or functions; or

2. Such conduct is necessary as an emergency measure to avoid an
imminent public or private injury which is about to occur by reason of a
situation occasioned or developed through no fault of the actor, and
which is of such gravity that, according to ordinary standards of
intelligence and morality, the desirability and urgency of avoiding such
injury clearly outweigh the desirability of avoiding the injury sought
to be prevented by the statute defining the offense in issue. The
necessity and justifiability of such conduct may not rest upon
considerations pertaining only to the morality and advisability of the
statute, either in its general application or with respect to its
application to a particular class of cases arising thereunder. Whenever
evidence relating to the defense of justification under this subdivision
is offered by the defendant, the court shall rule as a matter of law
whether the claimed facts and circumstances would, if established,
constitute a defense.